This invention relates to a new improved choke control and more particularly to an automotive choke control with improved heating and cooling characteristics to more closely reflect an analogue of the engine temperature.
Conventional automotive choke controls have used a thermostat metal coil thermally-coupled to the motor to open a choke valve for permitting more air to enter a carburetor as the motor heats up. In this way the conventional control is to provide a rich air-fuel mixture to the motor when the motor is first started to facilitate motor starting, while supplying a leaner air-fuel mixture for achieving greater fuel economy after the motor has reached its normal operating temperature. These controls, however, are unsatisfactory under certain conditions (i.e. high altitudes) and generally not quick enough in their response.
To improve the control, a self-regulating electrical resistance heater is used to provide quicker response by the coil and thereby minimize operation with the rich air-fuel mixture. The use of the self-regulating heater greatly improved the operation of the control but heat loss from the control to its surrounding housing still remains a problem. The heat loss retards the heat-up response time and increases the rate of cool down, both of which inhibit proper operation of the choke control. Additionally a larger heater is needed to try to overcome these difficulties and the associated costs increases it provides.
Accordingly, it is an object of this invention to provide a novel and improved control for an automotive choke valve; to provide such an improved control with improved heating and cooling characteristics to minimize the quantity of pollutants discharged by an automotive motor to provide such a control which is reliable and which has a long service life; and to provide such a control which is of simple, inexpensive, and rugged construction.